Quartz crystal watch

ABSTRACT

A quartz crystal watch comprising a quartz crystal oscillator for generating relatively high frequency signals, a frequency divider circuit for reducing and converting the frequency of the oscillated signals from said oscillator to predetermined frequencies of clock pulse, a pulse width converter for reducing the pulse width of output pulse signals from said frequency divider circuit, a motion transducer for converting the amplified output signals from the amplifier pulse width converter to the corresponding mechanical motions, and a gear train mechanism driven by said mechanical motions, the gear action of said gear train being made to follow the accurate time.

United States Patent 1191 Jan. 23, 1973 Ito 1541 QUARTZ CRYSTAL WATCH[75] lnventorz: Kazuo Ito, Tokyo, Japan [73] Assignee: Kabushlki KaishaDaini Seikosha,

Tokyo, Japan 122] Filed: Dec. 14, I970 [21] Appl. No.: 97,983

[30] Foreign Application Priority Data Jan. 28, 1970 Japan ..45/70ll[52] US. "5f. 58/23 A, 307/266 [51 1 Int. Cl. ..G04c 3/00 [58] Field ofSearch ..58/23 R, 23 A, 28 H; 3/28, 3/28 B; 307/266; 318/128, 129, 130,131, 132; 331/116 M [56] References Cited UNITED STATES PATENTS3,597,634 8/1971 Flaig ..58/23 A X Primary Examiner-Richard B. WilkinsonAssistant Examiner-Edith C. Simmons .lackmon Att0rneyBlum, Moscovitz,Friedman & Kaplan [57] ABSTRACT A quartz crystal watch comprising aquartz crystal oscillator for generating relatively high frequencysignals, a frequency divider circuit for reducing and converting thefrequency of the oscillated signals from said oscillator topredetermined frequencies of clock 6 Claims, 8 Drawing FiguresPATENIEDJAHZE I975 sum 1 'ur 3 L T i m PATENTEDJANZ 3197a sum 2 BF 3 all L BACKGROUND OF THE INVENTION This invention relates to a quartzcrystal watch and particularly to a quartz crystal watch having a geartrain driven in synchronization with the clock pulse of one second cyclewhich can be obtained by dividing the oscillating frequency from aquartz crystal oscillator having a quartz crystal vibrator. It is knownthat the oscillating frequency ofa metal tuning fork can be utilized asa time standard by converting the vibrations of the tuning fork to arotary motion by means of a ratchet mechanism, and transferring theresultant rotary motion to a known gear train, thereby working a watchto indicate the proper time. In respect of time accuracy, however, it isdesirable to employ a quartz crystal vibrator rather than a metal tuningfork because the former is superior in its oscillating frequencycharacteristics to the latter. Furthermore, quartz crystal vibrator hasother advantages in that, generally speaking, the higher the oscillatingfrequency, the more accurate and smaller in Size. Such advantages make aquartz crystal vibrator suitable for a wrist watch.

On the other hand, the said oscillating frequency signals are too highfor the said converter to follow, so that it is necessary to provide afrequency divider circuit, thereby reducing the oscillating frequency insuch a degree that said motion converter can easily follow theoscillating frequency. However, there is another problem in that theprovision ofa frequency divider circuit gives rise to an increasedconsumption of power, thus badly reducing its usefulness for a wristwatch.

SUMMARY OF THE INVENTION This invention overcomes the above-mentionedproblems. It is one of the objects of the present invention to provide aquartz crystal watch in which the 7 frequency of the oscillated signalfrom a quartz crystal oscillator is converted through a divider circuitto a frequency ofa pulse signal which a converter can easily follow, andin which the pulse width of said pulse signal is reduced through a pulsewidth converter and the output pulse signal from said pulse widthconverter is transmitted to the gear train through the above-mentionedconverter.

Another object of the present invention is to provide a quartz crystalwatch which requires such a small amount of power that an electric cellcan be satisfactorily used as a power source.

Another object of the present invention is to provide a quartz crystalwatch in which the driving coil of the converter is divided into twoparts to miniaturize the driving coil. According to the presentinvention, there is provided a quartz crystal watch comprising a quartzcrystal oscillator for generating relatively high frequency signals, afrequency divider circuit for reducing and converting the frequency ofthe oscillated signals from said oscillator to predetermined frequenciesofclock pulse, a pulse width converter for reducing the pulse width ofoutput pulse signals from said frequency divider circuit, a poweramplifier for amplifying the output pulse signals from the saidfrequency divider circuit, a motion transducer for converting the outputsignals from the'amplifier to corresponding mechanical motions, and agear train mechanism driven by said mechanical motions, the gear actionof said gear train being made to indicate the proper time. The nature,principle, and details of the invention will be best understood byreference to the following description, taken in conjunction with theaccompanying drawings in which like parts are designated by likereference numerals.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing oneembodiment of a quartz crystal watch according to the present invention;

FIG. 2 shows an example of circuit diagram of the quartz crystaloscillator of FIG. 1;

FIG. 3 illustrates an example of circuit diagram of the frequencydivider circuits of Ci. 1;

FIG. 4 represents an embodiment of circuit diagram of the pulse widthconvertor of FIG. 1;

FIGS. 5A, 5B schematically show examples of input wave form and outputwave form respectively at the pulse width converter of FIG. 4;

FIG. 6 illustrates an example of circuit diagram of the power amplifierof FIG. 1; and

FIG. 7 shows a plan view of the motion transducer of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION One of the embodiments of thisinvention will be hereinafter explained with reference to the drawings.

In FIG. 1, showing a block diagram of a quartz crystal watch, 11represents quartz crystal oscillator for emitting relatively highfrequency signals of high accuracy, and 12 the frequency divider circuitfor suitably reducing and converting the frequency of oscillated signalsfrom the quartz crystal oscillator 11 to the clock pulse ofpredetermined frequency. The output clock pulse from the frequencydivider 12 is relatively large in its pulse width, so that whentransmitted as it is to the subsequent stage, a large amount of power isconsumed. Accordingly, it is preferred that the output clock pulse widthbe reduced as much as possible by passing it through the pulse widthconverter 13. The output pulse signals emitted out of the pulse widthconverter 13 will then be passed to power amplifier 14, and suitablyamplified. The amplified signals are then transmitted to the motiontransducer 15 for converting the signals to the corresponding mechanicalmotions. These mechanical motions produced by the motion converter 15are then transmitted to the gear train 16, and accurate time can beobtained by the gear action of the gear train 16. The circuit shown inFIG. 2 constitutes back coupling oscillators 11a wherein quartz crystalvibration unit 21, having a natural frequency of eg 16,384 hz, isemployed and two n-p-n type transistors TRl and TR2 are connected to thevibration unit 21 with the vibration unit 21 being positioned inbetween. In this instance the quartz crystal vibration unit willmaintain high accurate natural frequency under the temperature in therange of 0 to 50 C. In a temperature range higher than 50 C, however, itis difficult to obtain the high accurate natural frequency, and it ispreferred to connect a temperature sensitive capacitor C1 between thevibration unit 21 and common emitter terminal 22 of said oscillatingcircuit for compensation of any disorders and to connect variablecapacitor C2 in the same manner as the temperature capacitor CI foreffecting a fine adjustment to the oscillating frequency as shown inFIG. 2. The oscillating circuit 11a constructed as above isexperimentally found to be able to derive oscillating frequency signalshaving an accuracy of more than 10 from the output terminal 23 under thetemperature ranging 30 C to 80 C.

FIG. 3 illustrates an embodiment of frequency divider 12a of frequencydivider 12 shown in FIG. 1. This frequency divider 12a is provided withinput terminal 31 in to which the oscillated frequency signals derivedfrom output terminal 23 of the oscillator 11a of FIG. 2 are added. Thepurpose of providing the frequency divider 12a is to divide theoscillated frequency signals (16,384hz in this instance) from theoscillator 11a, and converting them to a clock pulse of l hz i.e;,corresponding to one second cycle. For example, the frequency divider 12a comprises two cascade connected astable multivibrators 32a and 32brespectively performing a quarter frequency division, and flipflopcircuits 33a 33j cascade connected to the astable multivibrator 32b andeach performing a half frequency division.

The frequency divider 12a as constructed above, can derive output pulsesignals of ,5 frequency of the input signals to be applied to the inputterminal 31 in from the output terminal 31 out. Accordingly, when thefrequency of oscillated signals to be transmitted to the input terminal31 in from the oscillating circuit 11a is 16,384 hz, pulse signals of16,384/2 l hz can be derived from the output terminal 31 out of thefrequency divider 12a.

The pulse width of output signals derived from the above-mentionedfrequency divider is generally about one half of the repeating cycle(one second in this instance) of the pulse as shown in FIG. 5A, so thatwhen such wide pulse signals are employed for driving a gear 7 trainmechanism, a large amount of power will be wasted, thus making anelectric cell undesirable as a power source for a wrist watch.

FIG. 4 illustrates an embodiment of pulse width con verter circuit 13for eliminating as much as possible wasteful consumption of power.Circuit 13 comprises a monostable multivibrator 13a provided with a pairof np-n type transistors TR3 and TR4, and its input terminal 41 in ispositioned in such a manner that pulse signals as shown in FIG. 5A isapplied from output terminals 31 out of the frequency divider 12a. Themonostable multivibrator 13a makes it possible to derive output signalshaving a pulse width determined by the time constant which is theproduct of resistance of a resistor R connected between the basetransistor TR3 and +8 power terminal 42, and capacitance of capacitor Cconnected between the collector of transistor TR3 and the base oftransistor TR4. With this construction, as shown in FIG. 5B, the pulsewidth of output signals to be derived from the monostable multivibrator13a can be prominently reduced (0.01 second in this instance) incomparison to the input signals, such as shown in FIG. 5A, applied tothe input terminal 41 in from the frequency divider 12a, thus reducingthe power consumption.

FIG. 6 is an embodiment of power amplifier 14 of FIG. 1, comprising aDarlington circuit 1421 having -a pair of n-p-n transistors TR5 and TR6.The pulse signals, as shown in FIG. SE, from the monostablemultivibrator 13a, are applied to the base input terminal of theDarlington circuit 14a. Between the collector output terminal and +8power terminal 42, driving coil L is connected for driving a gear trainmechanism. Diode D connected between the opposite ends of the drivingcoil L operates to shunt the counter electromotive force indiced in thedriving coil L.

FIG. 7 shows an embodiment of the motion transducer of FIG. 1, wherein apair of driving coils La and Lb, connected between the collector outputterminal of Darlington circuit 14a and +3 power terminal 42, are eachwound around bar-shaped ends 64a and 64b of respective cores 63a and 63bsymmetrically positioned toward both ends of and in parallel with theconductive substrate 61. At the other ends of each core 63a and 63bthere are formed semicircular projections 62a and 62b in such a mannerthat these projections 62a and 62b form an incomplete circular spacebetween them as shown in FIG. 7. At the center of the circular spacethere is pivotally provided a bar-like permanent magnetic piece 66 insuch a manner that both ends thereof are normally positioned at thevicinity of the approaching points of opposing projections 62a and 62b.On the permanent magnetic piece 66, a lever 68 is provided having onboth its ends palletjewels 67a and 67b, and pivotally fixed by thecenter.

61a and 61b are the curved parts of the substrate 61 and engagedmagnetically with the outer ends 641 and 64b of the cores 63a and 63brespectively. When the one second cycle clock pulse as shown in FIG. 5Bis applied to the base input terminal of the Darlington circuit 14a, thepulse signals are then transmitted to the driving coils La and Lb andmagnetize a pair of cores 63a and 63b, thereby inducing a pair ofmagnetic poles comprising N-pole and S-pole as shown in FIG. 7 at thefacing ends of the semicircular projects 62a and 62b. Thus the inducedmagnetic poles repel one end of the permanent magnetic piece 66 andsimultaneously attract the'other end thereof, thus effecting apredetermined rotary moment to the permanent magnetic piece 66. As lever68 is fixed to the permanent magnetic piece 66, rotary motion of thepiece 66 also provides the rotary motion of the lever 68 in the samedirection and amount as those of piece 66. The rotary motion of lever68, on the other hand, provides the rotary motion of escapement wheel161 of the gear train by the engagement of one of the teeth of wheel 161to the pallet jewels secured to both ends of the lever 68, at the rateof speed wherein one engagement effects a half pitch of movement in thedirection of the arrow 69.

When pulse signals go out, a pair of magnetic poles, once induced at theprojections 62a and 62b, disappear and. the permanent magnetic piece 66returns to the stable status, i.c., both ends thereof being positionedat the vicinity of the approaching point of opposing projections 62a and62b. As the piece 66 returns to the stable status, another pallet jewelfixed on the other end of lever 68 pushes the escapement wheel 161 by ahalf pitch in the direction of arrow 69, thereby making one second pulsecycle to conform with time indication of one second. by rotatingescapement wheel 161 by one J tooth.

In the quartz crystal watch described above, any time errors that mightoccur can be easily compensated by adjusting capacitance of variablecapacitor shown in FIG. 2.

The invention can be modified within the range which does not constitutedeparture from the spirit and scope of the invention as set forth in theappended claims.

What is claimed is:

l, A quartz crystal watch comprising a quartz crystal oscillator forgenerating relatively high frequency signals, a frequency dividercircuit for reducing and converting the frequency of the oscillatedsignals from said oscillator to predetermined frequencies of clockpulse, a pulse width converter for reducing the pulse width of outputpulse signals from said frequency divider circuit to minimize powerconsumption in the operation of said watch, an amplifier for amplifyingthe output pulse signals from said pulse width converter, motionconverter means including driving coils to which said amplifier outputsignals are applied, a pivotably mounted lever and magnetic circuitmeans coupling said lever and driving coils for producing correspondingmechanical motions in said lever in response to said amplifier outputsignals, and a gear train mechanism driven by said mechanical motions,the gear action of said gear train being made to follow the proper time.

2. The quartz crystal watch according to claim 1, wherein said quartzcrystal oscillator includes a quartz crystal vibrator having arelatively high natural frequency, and a temperature sensitive capacitorfor compensating temperature coefficient of said vibrator.

3. The quartz crystal watch, according to claim 1, wherein said quartzcrystal oscillator includes a variable capacitor for effecting a fineadjustment of oscillating frequency.

4. The quartz crystal watch, according to claim 1, wherein saidfrequency divider circuit comprises a plurality ,of flip-flop circuitscascade connected each other.'

5. The quartz crystal watch, according to claim 1, wherein saidfrequency divider circuit comprises a combination of astablemultivibrators and flip-flop circuits.

6. The quartz crystal watch according to claim 1, wherein said motionconverter means comprises driving coils symmetrically provided in spacedrelation, a pair of cores each having a bar-like end inserted into saidcoils and a semicircular projection on the other end, a bar-likepermanent magnetic piece pivotally provided at the center of a circularspace formed by said semicircular projections, and a lever having oneach end a pallet jewel, said lever being mounted for movement togetherwith said permanent magnetic piece, so that said gear train can be movedat the prescribed rate pitch through said palletjewels.

1. A quartz crystal watch comprising a quartz crystal oscillator forgenerating relatively high frequency signals, a frequency dividercircuit for reducing and converting the frequency of the oscillatedsignals from said oscillator to predetermined frequencies of clockpulse, a pulse width converter for reducing the pulse width of outputpulse signals from said frequency divider circuit to minimize powerconsumption in the operation of said watch, an amplifier for amplifyingthe output pulse signals from said pulse width converter, motionconverter means including driving coils to which said amplifier outputsignals are applied, a pivotably mounted lever and magnetic circuitmeans coupling said lever and driving coils for producing correspondingmechanical motions in said lever in response to said amplifier outputsignals, and a gear train mechanism driven by said mechanical motions,the gear action of said gear train being made to follow the proper time.2. The quartz crystal watch according to claim 1, wherein said quartzcrystal oscillator includes a quartz crystal vibrator having arelatively high natural frequency, and a temperature sensitive capacitorfor compensating temperature coefficient of said vibrator.
 3. The quartzcrystal watch, according to claim 1, wherein said quartz crystaloscillator includes a variable capacitor for effecting a fine adjustmentof oscillating frequency.
 4. The quartz crystal watch, according toclaim 1, wherein said frequency divider circuit comprises a plurality offlip-flop circuits cascade connected each other.
 5. The quartz crystalwatch, according to claim 1, wherein said frequency divider circuitcomprises a combination of astable multivibrators and flip-flopcircuits.
 6. The quartz crystal watch according to claim 1, wherein saidmotion converter means comprises driving coils symmetrically provided inspaced relation, a pair of cores each having a bar-like end insertedinto said coils and a semicircular projection on the other end, abar-like permanent magnetic piece pivotally provided at the center of acircular space formed by said semicircular projections, and a leverhaving on each end a pallet jewel, said lever being mounted for movementtogether with said permanent magnetic piece, so that said gear train canbe moved at the prescribed rate pitch through said pallet jewels.